This invention relates to the field of surgical endoscopy, specifically to improvements in skin seals and cannulas.
Surgical endoscopy is a surgical technique of using small diameter long-handled tools such as graspers, forceps, scissors, refractors, dissectors, and clamps specially designed to be inserted through small incisions in the skin (or other openings in the body) to perform operations within the body. The surgeon performing the surgery often cannot see the operation directly and must watch the procedure on a video monitor fed by an endoscopic camera or endoscope. Endoscopic surgery replaces open surgery that requires large incisions, essentially opening the body cavity completely, in order to perform surgery deep within the body. Endoscopic techniques have been used for gall stone removal, gall bladder removal, hernia repair, tumor removal, lymph node removal, appendectomy, and many other operations. Endoscopic surgery is also called laparoscopic surgery, video assisted surgery, minimally invasive surgery, and bandaid surgery, but throughout this specification the term endoscopic surgery or laparoscopic surgery will be used.
To illustrate the background of the inventions described below, the example of the laparoscopic cholecystectomy, hernia repair, or lymphadenectomy, as well as the operation for harvesting a blood vessel, will be used to illustrate both the old laparoscopic procedures and the new laparoscopic procedures now possible with the new devices. In the old procedure, a working space was created in the abdomen using the process called pneumoperitoneum or insufflation. Insufflation is the process of injecting gas into the body to blow it up like a balloon, creating a chamber filled with gas. When performed on the abdomen, the peritoneum is inflated and the procedure is known as pneumoperitoneum. The procedure can be used for inflating a space between the peritoneum and the skin to permit laparoscopic hernia repair, as illustrated in U.S. Pat. No. 5,496,345, issued to Kieturakis et al. and entitled xe2x80x9cAn Expansible Tunneling Apparatus for Creating an Anatomic Working Space.xe2x80x9d Insufflation can be used also to inflate a tunnel shaped working space over a blood vessel, to facilitate blood vessel harvesting, as described in U.S. patent application Ser. No. 08/267,484, entitled xe2x80x9cExtraluminal Balloon Dissection Apparatus and Methods,xe2x80x9d incorporated herein by reference. While the chamber is filled with gas, the surgeon inserts long slender laparoscopic tools through trocars and cannulas that pierce the skin and provide access ports into the insufflated chamber.
For abdominal surgery, such as a cholecystectomy, (gall bladder removal), the insufflation is accomplished by the following procedure. An incision is made at the lower edge of the belly button or umbilicus. The surgeon uses his fingers or a blunt dissection tool, such as a blunt nosed obturator, to uncover the fascia or abdominal muscles, then a large needle, referred to as a Verres needle, is inserted into the abdomen or peritoneal cavity. The Verres needle punctures the fascia and peritoneum that cover the abdomen. A pressurized gas such as CO2 is injected into the abdomen through the needle, in effect inflating the abdomen like a balloon. After the abdomen is inflated, the Verres needle is removed. After the needle is removed, trocars and cannulas are inserted into the space created by the insufflation. Endoscopic instruments, including an endoscope or laparoscope, scissors, graspers, etc., are inserted into the abdomen through the cannulas and manipulated to dissect tissue surrounding the gallbladder, remove the gall bladder, and stitch the internal wounds.
To harvest the saphenous vein using laparoscopic procedures, the surgeon may insufflate a tunnel shaped workspace over a blood vessel. The tunnel is first created using obturators, tunneling devices, or balloons inserted through small incisions along or over the saphenous vein. After the tunnel is created, the surgeon may insert skin seals and cannulas, and insufflation gas is injected through one of the trocars. While the tunnel is insufflated, the cannulas permit the surgeon to insert laparoscopic instruments into the tunnel to perform surgery on the saphenous vein.
The cannula used in the procedures described above is a length of rigid tube. The trocars and cannula are designed to allow laparoscopic instruments to pass through them and prevent gas from escaping the abdomen or other insufflated work space. The cannula may have a flapper valve or a trumpet valve inside that opens to allow an endpscope, laparoscope, or other instrument to pass through, and the valve closes when the laparoscope is removed. Some trocar/cannula devices also contain a duckbill valve to assist in sealing the trocar. The cannulas are typically about 6 inches or 15 centimeters long, and come in diameters matching various laparoscopic devices, generally from 2 to 15 mm.
Some surgeons use bare cannulas, secured only by a tight fit with the skin and fascia. However, cannulas frequently slip out of the body during use, disrupting the procedure and possibly endangering the patient. To prevent this danger, surgeons have devised a variety of methods to secure the cannula to the body and prevent it from slipping out of the body. Some cannulas are provided with threaded sleeves fixed to the cannula. Some cannulas are provided with a threaded gripper with a smooth inner bore that matches the size of the cannula, so that the cannula can slide inside the gripper as shown in FIG. 2. The gripper stabilizes the cannula so that it will not slip out of the body inadvertently, but can be easily slipped out when the surgeon wants. The threaded gripper is simply screwed into the incision in the skin. This option permits the ready insertion and removal of smooth walled cannulas by sliding them in and out of the gripper. Other grippers have been used, such as the gripper with expandable arms, the gripper with inflatable balloon on the outside, and the Hasson cannula. These devices are illustrated in Oshinsky, et al., Laparoscopic Entry and Exit, reprinted in Urologic Laparoscopy at 91-101 (Das and Crawford ed. 1994). These devices are variously referred to as threaded skin seals, screw skin seals, skin anchors, obturators, grippers, trocar stabilizers, or cannula stabilizers.
The surgeon usually needs to place several trocars and cannulas into the abdomen and inserts as many as needed to accomplish the intended operation. The first cannula placed through the belly button is used to insert a laparoscope so that the placement of other trocars and cannulas can be viewed from inside the abdomen. After several cannulas are in place, the surgeon can view the procedure through any port and can insert laparoscopic scissors, cutters and graspers, and other tools through the cannulas in order to perform the surgery. The typical endoscopic graspers 3 used for stitching inside the abdomen are shown, deployed inside the cannulas, in FIG. 2. A bare cannula 4 is used with endoscopic graspers 3a. Another pair of laparoscopic graspers 3b is inserted into a cannula 4a that is inserted through a threaded gripper 5. A third cannula 6, shown with a threaded outer surface, is provided for an endoscope 34 that is inserted into the workspace to provide the surgeon with a video view of the graspers 3a and 3b and body tissue.
The arrangement of the cannulas and trocars is required because the abdomen must be inflated to make room for the surgeon to work. The small diameter of the cannulas keeps the incisions small, and the matching diameter of the laparoscopic instruments is necessary to prevent leakage of the insufflation gas from the abdomen. Laparoscopic instruments of various designs are available, and they generally are about 5 to 12 mm in diameter (to match the inside bore of the cannulas) and about 10 to 40 cm in length. They are long and therefore difficult to use, and they are usually used when the surgeon can see them only through the laparoscope. Modern laparoscopic procedures require the surgeon to view the procedure on a video monitor. It may take a surgeon a lot of practice before becoming comfortable and skillful with the laparoscopic graspers, grippers, and scissors. These tools are more difficult to use than the surgical tools that every surgeon uses in normal surgery, such as those shown in FIG. 3, in use during open laparotomy. The normal graspers are shown in use while the surgeon is tying off a suture. This normal procedure is familiar to a large number of surgeons. The normal surgical graspers 7a and 7b are shown in use in FIG. 3, suturing body tissue 8 with suture 9, and it can readily be appreciated that the laparoscopic graspers shown in FIG. 2 require significantly more skill than the normal surgical tools. One of the drawbacks of the known cannulas and grippers is that they are adapted to admit only relatively narrow instruments, and are therefore generally unsuited for use with ordinary open incision surgical tools.
It would be advantageous to use normal surgical tools during laparoscopic procedures, but this is usually not permitted by the typical construction of the trocars and cannulas that are too narrow, long, and rigid to permit passage of the normal surgical tools. Most surgeons are very well trained in using conventional nonendoscopic instruments, such as the open incision graspers shown in FIG. 3, and numerous procedures involving the graspers such as tying off a suture are well known and well practiced. The endoscopic instruments shown in FIG. 2, on the other hand, are not well known and well practiced, and generally require significantly more skill than the more familiar open incision instruments. Thus, there is a need to provide cannulas and grippers that would accommodate the instruments used in open incision procedures.
In a typical endoscopic or laparoscopic operation, a surgeon creates a working space inside the body through insufflation. To create the working space for abdominal surgery, the surgeon makes a small incision at, for example, the inferior margin of the umbilicus 1 as shown in FIG. 1, and then uses his fingers or a dissecting tool, such as a blunt nosed obturator, to prepare a point of injection. The surgeon then inserts a Verres needle 2 into the abdominal cavity, and causes a pressurized gas such as CO2 to flow through the needle and into the abdominal cavity. This inflates the abdomen, as shown in FIG. 1, and provides a working space for the surgeon. The needle may then be removed, and a cannula or trocar/cannula combination may be inserted into the incision. Additional incisions may also be made, and the first incision may be used to insert a laparoscope to assist in the placement of the other incisions. The additional incisions may each receive a cannula and, once several cannulas are in place, the surgeon can view the procedure and/or insert laparoscopic scissors, cutters, graspers, or other tools through any of the cannulas.
As mentioned above, the trocars and cannulas can be used in endoscopic blood vessel surgery, laparoscopic cholecystectomy, and laparoscopic hernia repairs where a workspace is created under the skin. In the blood vessel harvesting operation where the saphenous vein is to be removed, a surgeon creates a tunnel between two small incisions over the saphenous vein. Then a cannula and skin seal are inserted into each incision. The tunnel is insufflated through one of the cannulas. In these procedures, the laparoscopic instruments are also inserted into the working space through the cannulas, and the surgeon can watch the surgery through a laparoscope inserted through one of the cannulas.
The devices presented herein allow for use of normal surgical tools (such as the forceps and scissors used in open incision surgery) in laparoscopic procedures. The skin seal is fitted with one or more balloons on the inner bore. These balloons can be inflated after the skin seal is inserted into the incision into the abdomen Placement of the skin seal can be accomplished as usual, with the aid of a blunt or sharp trocar or cannula placed within the threaded skin seal. The threaded skin seal can be made of rigid plastic, as is customary, or preferably it may be made of soft and pliable material such as latex or silicone rubber. When the threaded skin seal is in place, the trocar may be removed and the balloon may be inflated until it expands to fill the inner bore of the threaded skin seal, thus sealing the bore to maintain the pressure created inside the abdomen with the insufflation gas. The balloons are soft and pliable and can conform around the elements of the instruments as they are moved about during use. Thus, normal or conventional surgical instruments may be passed between the balloons. Both normal surgical instruments and laparoscopic instruments may be inserted into the body through the balloons without disrupting the seal created by the balloons. The balloon is soft and pliable so that normal surgical tools may be operated inside the inflated balloon segments, and the balloon segments will not hamper the operation of the tool to a significant degree. The skin seal may be provided with a balloon membrane that expands outside the lumen of the skin seal to create a dumbbell, dog bone, or bowtie shaped balloon which pinches the skin and, when necessary, fills the lumen of the skin seal.
More than one tool may be inserted through a single skin seal because the balloons are sufficiently pliable and may be inflated to a lesser degree. In this manner, normal surgical instruments may be used in laparoscopic procedures, taking advantage of the fact that they are easier to use and more surgeons know how to use them, compared to the long laparoscopic instruments. The balloon filled skin seal may be used also as a seal for laparoscopic incisions which are no longer necessary or which the surgeon desires to plug temporarily while still leaving a skin seal in place for later use.